Timing mechanism



Marc]; 9, 1943.

w. D. HALLORAN 2,313,065

TIMING MECHANISM Filed Aug. 27, 1958 2 Shets-Sheet 1 I II I Will '//I/////// III/ March 9, 1943- w. D. HALLORAN TIMING MECHANISM Filed Aug. 27, 1958 2 Sheets-Sheet 2 I I I! I llIY/I/ [III 182 r\\ 111/ 111/ III 1/ AA/ I If Patente d Mar. 9, 1943 TIMING MECHANISM William D. Halloran, River Forest, lll., aasignor to Sears, Roebuck and 00.. Chicago, IIL, a corporation of New York Application August .27, 1938, Serial No. 227,048

' 6 Claims. (Cl. 200-35) This application pertains to controls, and is concerned more particularly with, but not limited to. the control of heating devices including stoves or ranges.

It is an object of my invention to provide an improved automatic control for a heating device whereby it may be made to furnish heat of a given intensity for a given length of time.

It is another object of the invention to provide a control for a heat transfer device which will enable the same to function automatically at different temperatures for different time intervals.

It is a further object of the invention to provide a control automatically operative to cause a device to operate first in one condition for a given time interval and then, at the close of that interval, to operate under a diflerent condition for a given time interval.

It is also an object to provide, in an apparatus such as a cooking stove, a control including a timer which may be manually set to cause a stove to deliver heat for a predetermined time interval at one temperature and automatically at the end of that interval to deliver heat at another temperature.

A further object is to provide a control mechanism automatically operative to maintain a device in different conditions at different times. and to automatically stop operation of the device.

Another object is to provide a control automatically operative to maintain a device in one condition of operation for a given length of time and to maintain the device thereafter in another condition oi. operation for an indefinite length of time.

A further object is to provide a control for selectively maintaining a device in one condition of operation for definite and indefinite periods.

It is another object to provide an improved quick-break switch.

Further objects and advantages of the invention will appear as the description proceeds.

The invention may be better understood upon reference to the following description and accompanying drawings, in which:

Fig. 1 is a section elevation of a control mechanism constructed in accordance with one form Fig. 4 is a fragmentary transverse sectionalview similar to Fig. 2, but with the parts in still another adjustment.

Fig. 5 is a fragmentary sectional view showing details of a switch control mechanism at the make or break of the switch.

Fig. 6 is a transverse sectional view taken as indicated by the line 6-4 in Fig. 1.

Fig. '7 is a fragmentary longitudinal sectional view taken as indicated by line 1-1 in Fig. 6.

Fig. 8 is a view similar to Fig. 1 but of a modified form of the invention. taken as indicated by the line 8-! in Fig. 9.

Fig. 9 is a transverse sectional view taken as indicated by the line 9-9 in Fig. 8.

Fig. 10 is a fragmentary sectional view similar to Fig. 8 but with the parts in a different adjustment.

Fig. ii is a longitudinal sectional view taken as indicated by the line ill I in Fig. 8.

Fig. l2is a fragmentary sectional view taken as indicated by the line l2-i2 in Fig. 9.

Fig. 13 is a sectional view of a dial stop taken as indicated by the line 13-13 in Fig. 11.

Fig. 14 is a sectional view taken as indicated by the line il-ll in Fig-11.

Fig. 15 is a view similar to Fig. 12 but shows a stop for the other dial.

Referring now more particularly to the form of invention illustrated for exemplary purposes in Figs. 1 to 7, there is provided a suitable casing on which is mounted as at ii a clock 22 having a spring (not shown) which is operatively connected with a stafl 23. also preferably connected to the hour hand (not shown) of the clock. Coupled to the stall 23 for rotation therewith. as at I, is a shaft 21, the other end 28 of which is suitably journaled as at 29. A hub 30 is mounted for rotation independently of the shaft 21. Secured to the hub as at 3| is a dial 82 preferably having time graduations it at its periphery 34 and arranged so that an arcuate portion thereof always projects through an escutcheon plate 35 mounted as at 30 on the casing. The graduations are preferably in minutes, although they may be in other units if desired, and the plate It preferably has a datum point (not shown) marked thereon for use in connection with such graduatlons.

The hub 30 has a sleeve extension on which is keyed as at 4i or otherwise fastened for rotation therewith a cam plate I! disposed within an opening 48 in a bracket 44 welded as at I! or otherwise suitably secured to the casing 20. The sleeve 40 has a shoulder 41 between which and the plate 42 a second plate It is rotatably mountand 48. 7

An electric circuit which may include heating elements, as will appear, for a stove, for example, includes connections 51 and 08 and a switch indicated generally at 59 and comprising astationary contact 60, a spring GI, and a switch blade 62 normally urged away from the contact 60 by said spring. The switch blade and spring are preferably connected as at 84 with, and insulated as at 60 from, the lever 62, so that the spring 05 assists the spring 8| in urging the switch blade to open position.

Plvotally mounted as at 60 on the cam plate 42 is a pawl 59 adapted to engage a ratchet l suitably mounted on the shaft 21 for rotation therewith. The pawl 69 is urged toward the ratchet III by a spring I2 carried by the cam 42 and, under certain circumstances, the pawl is held out of engagement with the ratchet by a pin It carried by the lever 03, the spring 05, or the combined effect of the springs 55 and SI, being greater than the opposing effect of the spring 12.

The cam 42 has a notch I5 having an abrupt. preferably radial drop surface It and a relatively gradually inclined cam surface II. The plate 48 has a substantially radial slot 80 of a size to accommodate the follower 04.

It will now be apparent that by turning the graduated disk 32 in the direction of the arrow 85 (Fig. 2), the cam 42 will rotate therewith so that the cam surface 11 will force the pin 54 radially outward until the pin 00 has fully taken up its lost motion in the slot 5|. By this time the pin 54 will be engaged with the outer periphcry of the cam 42. The upright 44 has a recess 8i into which the follower is projected by this operation. This action takes place against the force of the springs 55 and SI and, as a result, the switch blade i2 is brought into engagement with the switch contact 60, closing a circuit of a heating element for a stove or the like, as will appear.

While the lever 52 is being cammed by the plate 42, the spring I2 moves the pawl 69 into engagement with the ratchet I0. As the rotation of the dial 32 is continued, the pawl transmits the rotary motion to the ratchet I0, which in turn transmits the motion to the shaft 21, thereby winding up the spring in the clock 22. Fla. 3 shows the arrangement of parts just before the completion of movement of the pin 00 in the slot SI and just before the pin 54 has reached its outermost position. Fig. 4 shows the arrange ment of parts after the disk 32 has been rotated one-half revolution, for example, so that the corresponding heat element will be on for, say, one-half hour. When the disk 22 is released at the desired adjustment, the clock spring turns the ratchet I0 which, acting upon the pawl 69 and pin 58, turns the cam 42 and dial 32 independently of the plate 40 in a clockwise direction until the pin 00 is at the left end of the slot SI as seen in Fig. 4, and the slot 801s in full register with the slot I5, as indicated in dotted lines at 81. Thereafter the plate 48 turns with the plate 42 as a unit. As this rotation continues, the follower 54 rides the outer periphery of the plate 42 free of the cam surface ll.

The follower 54 may be of any desired transverse shape. For illustrative purposes it is shown round. Its passage from the corner of the slot 80 as shown in full lines in Fig. 5 fully into said slot as shown in dotted lines in Fig. 5, takes an appreciable period of time, so that if the switch 59 were set to commence to open as the follower commenced to mcve radially inward, the opening of the switch blade would be slow and, before many operations, the switch points would be burned and rendered useless. In accordance with the present invention the switch is initially closed substantially before the follower 54 reaches its radially outermost positionfor example, when it is in the position shown is dotted lines in Fig. 5so that when the follower is at its outermost position (full lines,,

Fig. 5), the spring BI has been flexed to a greater extent than is required to effect engagement between the contact 60 and the switch blade 62, so that the switch engagement therebetween is under pressure. Accordingly, during the aforesaid time interval, the switch remains fully closed, and the switch does not open until the follower is substantially completely aligned with the slot 00, as shown in dotted lines in Fig. 5, so that its movement radially therein is precipitous and thus the opening of the switch is practically instantaneous, resulting from the excess of the force of the springs 05 and GI over the force of the spring I2.

It will be observed that while the follower is riding the periphery of the plate 48, the pin II is spaced from the pawl 68 so that there is no interference with the operation of the pawl in cooperation with the ratchet I0. As the follower moves into the slot 80, the pin I3 is ad- Jacent the pawl 69. As the movement of the follower proceeds, the pin I3 forces the pawl 59 free of the ratchet 1.0, as will be understood upon reference to Fig. 2, which may be said to show the relation of the parts at the beginning of the adjusting movement and at the end of the operating movement.

Mounted to rotate with the shaft 21 is another hub to which is secured at El a dial 92 having suitable graduations 93 at its periphery 94 for the purpose heretofore described. The hub 80 has a sleeve extension 95 to which a cam 98 is keyed as at 91 or otherwise secured for rotation therewith. An upright 90 welded as at 89 or otherwise suitably secured to the casing 20 has an opening I00 receiving the cam 98. Rotatabiy mounted on the sleeve extension 95 is a plate I02 having an arcuate slot I03 receiving a pin I04 extending from the cam 08. Pivotally mounted as at I00 on the upright 90 is a lever I06 having a cam follower or pin I0'I urged radially inwardly by a spring I08 anchored to the upright 98 and lever I06. An electric circuit containing a heating element to be controlled by the mechanism about to be described includes wires or binding posts IIO and III, leading to aswitch H2. The switch includes a stationary contact II! and a spring II4 to which is connected a switch blade III as by a connector III which may serve also to mount the spring and blade on the lever I04. The lever I04 is insulated as at Ill from the spring Ill and blade 5. The cam 80 has a notch I20 having an abrupt wall HI and a relaone limit of relative movement as shown in Fig. 6 as determined by the pin I04 and slot I00, and to be at least partially out of register therewith at the other limit as may be gathered upon reference to Fig. 4 showing the previously described switch construction.

Since the disk 02 and cam are mounted for rotation with the shaft 21, it will be observed that when the dial 02 is rotated in the direction indicated by the arrow I21 (Fig. 6), the shaft 21 will turn in a direction to wind up th clock spring. At the initial rotation of the dial 02, the cam surface I22 forces the follower I01 radially outward against the force of the springs I00 and H4, the follower preventing rotation of the relatively loosely mounted plate I02, and the pin I04 moving in the slot I00. When the cam surface I22 has completed its camming action, the follower I01 is about to pass out of the notch I20, and the pin I04 is at the other limit of the slot I03. As the dial 02 is turned farther, the plate I02 rotates with the cam 00 and forces the follower farther outward and into a notch I00 in the upright 00, and continued rotation of the disk 02 causes the follower to ride on the outer periphery of the plate I02.

Before the follower I01 commences to pass out of the notch I20, the blade II engages the contact 3, closing the switch H2 and turning on the heating element controlled by said switch.

It will be observed that the lever I00 has an extension I25 (Fig. 1) adapted for engagement with the blades of two additional switches I00 and 101. The switch I00 is connected at I40 to a neutral point between the heating elements I and I42, and to a neutral wire I43 in the line I44. The switch I01 is connected in series with the switch I00 through a pilot lamp I40 and is also connected with a power wire I41 of the line. The switch I I2 is connected to the power wire I41 and to the heating element I. When the lever I00 closes the switch I I2, the arm I00 of the lever at the same time closes the neutral wire and pilot lamp switches I00 and I01, respectively, simultaneously illuminating the lamp I40 and energizing the heating element I.

When the lever 00 closes the switch 00, the switch 00 is connected by the wire 01 to another power wire I00. and by the wire 00 to the second heating element I42, so that, when the neutral switch I00 and the switch 00 are closed, the heating element I42 is energized.

Inasmuch as the neutral switch I30 can be closed only when the switch H2 is closed, it follows that either the heating element I alone is on or both of the heating elements HI and I42 are on.

The switch I I2 is closed and opened in the same manner as the switch 00, so that further description of this structure is unnecessary.

In operation, if it is desired to use only the heating element Hi, the dial 02 is turned in the direction indicated by the arrow I21 until the datum point on the plate 30 indicates the length of time it is desired to use the element MI. The eflect of the turning of the dial is to wind the spring of the clock 22, and the spring, when released, will proceed to unwind so that when the time interval for which the device is set expires the switch III will open, the blades of the switches I00 and I01 being spring-pressed against the lever arm I00 so as to swing to open positions when the switch I i2 is opened.

When the dial 02 is rotated in a direction to close the switch I I2, it has no effect whatever on 70 the dial 02, since the pawl 00 is out of engagement with the ratchet 10, so that the ratchet merely idles relative to the dial 02 and the parts rotatable therewith. This insures against the taming on of the heating element I02 when the use of only the element I is desired. When it is desired to use both elements I and I42, assuming the switches H2 and 00 are open, the dial 32 is rotated in the direction indicated by the arrow 00 to the desired extent. As has been explained, the rotation of the dial 02 effects engagement between the pawl 00 and ratchet 10. causing the shaft 21 to rotate and wind the clock spring. Inasmuch as the dial 02 and cam 00 are rotatable with the shaft 21, they rotate at the same time that the dial 021s rotated, so that rotation of the dial 22 results in the closing of all of the switches, thereby energizing both heating elements I and I42. The switch control mechanisms are so arranged that with the adJustment made as just explained they will all open instantaneously and at the same time.

However, it may be desired to have both elements I and I42 on at the same time for a given interval, say 10 minutes, for example, and only the element ill on thereafter, say for a period of 30 minutes, for example. These results may be obtained as follows: With all the switches open the dial 02 is turned 10 graduations and, after the dial 22 is stopped. the dial 02 is turned 30 more graduations, bringing the setting of the dial 02 to 40. During this rotation of the dial 02, the pawl 00 will slip, so that the dial 02 will remain at its setting. The dial 02 is then released and all switches will remain closed for the selected period of use of both elements I and I42 as determined by the setting of the dial 02, and at the end of that period the switch 00 will open but the remaining three switches will remain closed until the dial 02 is returned to its oil setting, whereupon said remaining three switches will open.

The clock 22 may be of a character to rotate the staff 20 once an hour or more or less slowly, as desired, depending upon the uses to which the same may be put.

In accordance with another form of'the invention, there is provided a clock I02 having a staff I00 connected to a clock spring (not shown) and coupled at I04 with a shaft I00 which may be journaled as at I00 in the casing I01. Mounted on the shaft I00 for rotation therewith is a dial I00 having suitable graduations I00 and having a sleeve extension on which are formed cams I000, b, and IBM, which may be identical. Each of these cams has a notch I0 I A follower roller I02 adapted to ride on the periphery of each of said cams is Journaled in a slot I04 in a spring switch blade I00 adapted to engage a contact I00 of a switch I01 and normally urged out of engagement with said contact by the resilience of the spring, which holds the followed in engagement with the periphery of the cam. The switch I01 is connected at I00 to a power wire I00 of the line I10 and at I00 to a heating element Ill and, by means of a wire I12, with a like switchcontrolled by the cam 100b, the latter switch being connected as at I10 with a neutral wire I14 of the line, completing a circuit. The switch controlled by the cam I00c is in series with a pilot lamp I10 connected to the wire I12 and to the power wire I00 and is in parallel with the switch I01.

It will thus be evident that these three switches are closed and opened simultaneously, and, when they are closed. the heating element III and pilot lamp I15 are energized. When the dial I52 is rotated in the direction indicated by the arrow I15 in Fig. 9, it winds the clock motor or spring and turns the cams so that the followers I02 ride on the peripheries thereof. I have shown in .de-

tail only one of the cams and switches, since all The casing I5! i'nay have a; datum point I11 for cooperation with the dial graduations I50. which may be in any desired units, such as minutes, so that the datum point and said graduations together indicate how long the clock spring will take to return the dial to the 08 or any other setting.

The dial preferably is in its off setting when the switch is open as shown in Fig. 10. It is apparent that as the dial is rotated in the direction to load the spring, as indicated by the arrow I15 in Fig. 9, each cam will force the follower I62 radially outward and close the switch I01. At such time. the roller I52 is at the bottom of its slot I64 (Fig. 10), and the corner I10 of the cam engages the roller so as to press the roller along a line to the left of.the roller axis, thereby blasing the roller and hence the switch blade I" toward and presently into engagement with the contact I55, closing the switch. The switch remains closed while the follower rides on or is tangent to the outer periphery of the cam. When the clock spring is being loaded by the dial, the cam holds the roller in the bottom of its slot.

As the clock spring rotates each cam as shown by the arrow I19 in Fig. 9. the cam moves the associated roller to the upper end of the associated roller slot. As soon as the cam point I10 passes above the axisof the roller, the opening pressure of the springi55 will cooperate with the cam point in forcing the roller instantaneously to the bottom of the slot I54 and at such time the roller is precipitated into the cam notch III and the switch I5! is opened. The switch is thereby opened with despatch so that burning of the contact points is avoided, as in the previousl described switch.

The dial I58 has an arcuate groove I02 into which a catch I 83, slidably supported as on the casing I51, may be projected. The catch has a slot I04 through which a connecting pin I05 passes, and the casing has a slot I88 through which a manipulating handle I80 connected to the catch I03 extends. The groove I02 has a stepped interruption I02 providing an inner shoulder I93 and an outer shoulder I94. The catch I02 may be adjusted to be engageable with one or the other of said shoulders. As the clock spring rotates the dial I55. the shoulders approach the catch. The shoulder I04 is so arranged that when it is substantially engaged by the catch I02 the dial is at its oil setting and the switch is open. This adjustment of the catch could be omitted, therefore. but is preferably employed in order that accidental movement of the dial in the wrong direction, which might injure the follower I52, may be prevented. When the catch is engaged with the shoulder I02, the switch is closed and will remain closed until the catch is manually released from the shoulder I03.

A bushing 200 about the shaft I55 is disposed within a cam "I to which is loosely keyed as at 202 a dial 200 having suitable graduations 204 in minutes or other suitable units, for cooperation with a suitable datum point 205 on the casins. A plate 201 has a pin 204 engaged in a recess 209 in the cam to rotate the same. Pivotally connected at 2 to the plate 201 is a pawl 2I2 having a tooth 2I2 urged by a spring 2I4 into engagement with a ratchet 2I5 keyed as at 2I6 to the shaft I55 for rotation therewith. The dial 203 has a recess 220 in which a lug 22I on the pawl 2I2 projects. The cam "I has a shoulder 222 engageabie with said lug.

The cam 20I and switch means 224 associated therewith are identical with those previously described in connection with the form of the invention appearing in Figs.'8 to 15 and, accordingly, the 7 previous \description will suflice. The switch 224 is connected as by a wire 225 with another power wire 220 of tlfe"-llne i 10, and by a wire 221 with another heating element 220 which, like the heating element "I, is connected to the neutral switch wire I2.

When the dial I58 is turned to windthe clock spring, the ratchet 2I5, being mounted to rotate with the shaft I55, turns and, through its engagement with the pawl 2I2, urged into engagement therewith by the spring 2i4, turns the plate 201. The plate 201, by means of its pin 205, turns the cam 2" so that all four cams are adjusted alike and hence all four switches will close together. Since there is no load tending to resist turning of the dial 202 at this time. the pressure of the spring 2 will be sufilcient to prevent the inertia of the dial 202 from taking up the slack at the loose connection 202 between the dial 202 and the cam 20I, so that the shoulder 222 will not kick the lug and thus will not withdraw the pawl from the ratchet.

Thus when it is desired to energize both heating elements "I and 228 it is necessary merely to adjust the dial I 50, and when, with such a setting, the catch I22 engages the shoulder I02, both elements will be on indefinitely at the will of the operator.

I! it is desired that only the element I'II be energized the dial I58 is adjusted to an extent to maintain the element III in operation for the desired period, and then the dial 202 is turned in the reverse direction as indicated by the arrow 230 in Fig. 14. Since this movement will be resisted by the clock spring, the dial 203 will take up the slack In the loose connection 202 and, at that time, the dial shoulder 22! will kick the dog 22I to such an extent as to remove the pawl tooth 2I3 from the ratchet M5. The turning of the dial 203 is continued until it is at its off setting, when its switch 224 will be open. If desired, instead of the procedure just described, the dial 203 may be held stationary while the dial I50 is turned to the desired setting.

If it is desired to operate both elements "I and 220 for a given period and thereafter to operate only the element I'II, the dial I 08 is adjusted to a point corresponding to the total length of time the element I'II is to operate, the dial 200 being allowed to rotate with the dial I50. After the dial I55 reaches its set position, the dial 203 is turned reverselv to such a point that its graduations indicate the desired length of time its switch 224 will remain closed. Now when, in response to the operation of the clock spring, the dial 202 reaches its of! setting, its switch 224 will open. thereby de-energizing the heating element 220. The heating element "I will remain energized until the dial I55 reaches its oil setting.

In order to prevent tampering or accidental reverse movement of the dial 202, I provide said dial with an areuate groove 235 which is interrupted. providing an abutment 220 engageable 3,318,066 with a dog 231, which may be mounted as at III on the casing, to prevent movement oi the dial 203 in the direction indicated by the arrow 2" beyond its off setting.

It will be seen from the foregoing that I have provided a simple quick-break switch construction for providing low and high heat for desired periods oi time.

Any number of additional heating elements may be employed, as will be understood by those skilled in the art.

The construction is extremely simple yet emcacious, and involves a minimum of parts which may be confined in a small space and yet are readily accessible for adjustment, repair and replacement.

Various changes coming within the spirit of the invention may be suggested by those skilled in the art, and hence I do not wish to be limited to the specific forms shown or uses mentioned, except to'the extent indicated by theappended claims, which are to be interpreted as broadly as the state of the art will permit.

I claim:

1. In a device of the class described, a switch, a clock having a spring, a shaft rotatable by said spring, said shaft being rotatable in a reverse directionto energize said spring, means operative upon the turning of said shaft in the reverse direction to close said switch and maintain said switch closed until the shaft has been rotated by said spring to a pro-determined position, means cooperating with said switch and the switch-closing means for providing a quick break for said switch when the said shaft reaches said position, and means independent of said switch for preventing movement of said shaft beyond said position in the direction of its rotation by said spring.

2. In a control for an electric range including a pair of electrically heated heating elements, a circuit for said elements, switches for the respective elements and included in said circuit, means controlled by a single member for maintaining both of said switches closed for a predetermined period, means for opening one or said switches at the close of said period, means for opening the other of said switches at the close of an ensuing pro-determined period. and means for rendering the last named means inoperative.

3. Timing mechanism comprising a motor, a shaft rotated thereby. a cam rotatable with said shaft, a switch having a blade with a follower ensageable with said cam. said cam being movable to rotate said shaft so as to close said switch and load said motor, said motor being thereafter operative to turn-said shaft and cam, said cam havn: a notch adapted to be alined with said follower after a pre-determined period of operation of said shaft by said motor, means urging said follower lntosaid notch to open said switch, and means o gageable with said cam,

5 independent of said iollower for preventing further rotation of said said switch is open.

4. Timing mechanism comprising a motor, a shaft rotated thereby. a'cam rotatable with said shaft, a switch having a blade with a follower engageable with said cam, said cam being movable to rotate said shaft so as to close said switch and load said motor, said motor being thereafter operative to turn said shaft and cam, said cam having a notch adapted after a pre-determined shaft by said motor, means urging said follower into said notch to open said switch, and means independent of said timing mechanism for delaying such alinement.

5. Timing mechanism comprising a motor, a shaft rotated thereby. a cam rotatable with said shaft, a switch having a blade with a follower onsaid cam being movable to rotate said shaft so as to close said switch and load said motor. said motor being thereafter operativo to turn said shaft ing a notch adapted to and cam, said cam havbc alined with said follower after a pre-determined period of operation independent of said of said shaft by said motor, means urging said follower into said notch to open said switch, means for preventing further rotation of said shaft by said motor when said switch is open, .and means timing mechanism for delaying such alinement. Y a

6. Timing mechanism comprising a motor. a shaft rotatable by said motor. a pair of devices for making available portions of a supply of en-. ergy, means including a pair of manually adlustable members cooperating with said shaft for controlling the respective devices, means cooperating with each member and the associated device to render said device inoperative when said member is in one position, said members being operative upon manual rotation thereof in the direction opposite to the direction of rotation of said shaft by said motor, to render said devices operative each for a period determined by the extent of rotational the respective member, one of said members having a one-way ovcrrunning drive connection with said shaft and the other member being fixed to said shaft, said one member being adjustable with said shaft in said opposite direction to a selected extent and said other member being thereafter adiustabie with said shaft in said opposite direction to a selected extent, said shaft during the latter adjustment moving independently of said one member, said shaft, when turned by said motor, turning both of said members. whereby the period of operation of each device will correspond to the original adiustment of its associated member, and means automatically operative after one of saiddevices has become inoperative for preventing the other device from becoming inoperative. V

wmrsu 1:. mm.

shaft by said motor whenv to be alined with said followerperiod of operation of said CERTIFICATE OF CORRECTION. Patent No. 2,515,065. March 9, 191,5.

WILLIAM D. HAILLORAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction ae follows; Page 2, second column, line 18, for is read --in-; page 5, second column, line 14.0,

for dial 82" read --dial 92--; line 62, for "followed" read -iollower-;

page 15., second column, line 18, for wire 12 read --wire l72-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 27th day of April, A. n. 1915.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

